Energy

From an X post by Jesse Peltan

People keep saying that “batteries are bad” because: “batteries don’t create energy. batteries consume energy.”

Nothing. Creates. Energy.

Energy is neither created nor destroyed.

“Energy production” and “energy consumption” are economic terms — not physics terms.

We don’t actually produce or consume energy. We direct energy.

The function of a battery is not upstream energy harvesting, but that’s also not the function of a thermal generator. The energy doesn’t come from the generator. The energy comes from the fuel. We have to extract, refine, and transport that fuel. The generator is there to dispatch that chemical potential energy as electricity when it’s needed.

That’s what batteries do too, because:

Batteries ARE generators. Batteries aren’t electromechanical generators, but neither are photovoltaics or fuel cells. Like chemical-fueled thermal generators, batteries convert chemical potential energy into electrical energy.

The difference with batteries is that the process has fewer steps and is easily reversible. Batteries provide a buffer, matching up supply and demand in time. They act as a cache, providing higher peak power at lower latency than a thermal generator of comparable mass or cost.

Batteries are an extremely useful tool for directing the flow of energy. Batteries don’t “create energy” — that’s true.

Nothing. Creates. Energy.

I keep seeing “sure, maybe solar works, but what about all the materials you need for the batteries?” A battery that can store 100% of the daily production of a solar panel – *weighs less than the solar panel.*

Batteries are the most mass efficient way to provide peak power. That’s why we use them on satellites.

Now, mass alone doesn’t tell you the cost of a system, but LFP batteries are made from abundant materials and can be manufactured with continuous roll to roll processes. Costs dropped by >85% in the last 10 years as manufacturing scaled and technology improved – and they’re still dropping. Batteries are not going to be the limiting factor. I can assure you.